The present invention relates to an article position estimating apparatus, a method of estimating article position, and an article search system for managing articles in a general house or office, and particularly, relates to an article position estimating apparatus, a method of estimating article position, and an article search system for appropriately showing the position of the article being looked for when inquired for the lost article by the user, when the positions of various articles such as daily necessities used for living in the general house, portable articles used in offices or the like are managed through an RFID tag technique or the like.
Recently, technical development in automation of article management including inventory management is advancing focusing on the business field of physical distribution or the like by the network technique, information processing technique, or the RFID tag technical development for automatically managing the article.
Patent document 1 (Japanese Unexamined Patent Publication No. 07-146362) is a prior art illustrating the general configuration example of the article search system. In this example, the RFID tags (hereinafter referred to as tags) are given to the articles, tag reading devices (hereinafter referred to as a tag reader) are scattered in the environment, and a terminal for performing article search is arranged. When the article looking for is specified from the terminal, each tag reader attempts to establish a communication with the tags given to the articles, and the location of the tag reader that has received a response from the tag of the article looking for is assumed as the location of the article looking for.
The above configuration may be applied in managing books in the library or the like. That is, the tags are given to books to be managed, and the tag reader is arranged on each shelf of the book shelf of the library. When the user inputs the book to search for from the terminal or the like, each tag reader looks for the tag having the ID of the book being searched. When the response is not made from the tag with respect to the inquiry from the tag reader, the book is assumed to be not in a communicating range of the relevant tag reader. When the response is made from the tag with respect to the tag reader, the book being looked for is assumed to be found, where the location of the tag reader that has received the response from the tag is assumed as the approximate location of the book being looked for. The user then moves to the location of the reader and only looks for the books around the relevant reader to obtain the target book.
The conventional system is starting to be used in various fields mainly for business since the location of the article can be managed with a very simple configuration. However, the issue accompanied therewith is that the tag readers must be closely arranged to an extent the tags given to the articles can communicate with one of the tag readers at any place in the environment where the articles are being managed to enhance the precision of the searched position. Therefore, the system may be used in business where a cost can be increased to a certain extent but cannot be used in houses where cost is an essential issue.
Patent document 2 (Japanese Unexamined Patent Publication No. 2000-357251) is a prior art that aims to manage the articles in the house, wherein one method of avoiding the above issue is disclosed. In patent document 2, the article managing device, a plurality of sensor units (tag readers), and tag units given to the articles are arranged, and the specification or estimation of the position of the articles becomes possible and current positions of a plurality of articles are found by managing the reception sensitivity at the article managing device of when receiving the tag information transmitted from the tag units through the plurality of sensor units. In this technique, active tags with built-in batteries are used since the electric waves of the tags must reach the plurality of sensor units that are relatively distant from each other. A method of transmitting at a timing (once a day to once a month) defined in advance is adopted to suppress consumption of battery.
Similarly, in Patent document 3 (Japanese Unexamined Patent Publication No. 2003-233715) that is a prior art that aims to manage the articles in the house, observing instruments (tag readers) are arranged at four corners etc. of the ceiling to collect and manage the living information such as behaviour history of a person in the room, positional information on the objects to be managed and the like. The data tags are attached to the objects to be managed, and the person carries a personal tag on his finger tips. The data tags and the personal tag hold the identifying information on the objects to be managed or the person, so that wireless information communication with the observing instruments becomes possible at a plurality of communication distances.
Patent document 1: Japanese Unexamined Patent Publication No. 07-146362
Patent document 2: Japanese Unexamined Patent Publication No. 2000-357251
Patent document 3: Japanese Unexamined Patent Publication No. 2003-233715
In patent document 2, the position of the article is determined based on the record of the last communication between the tag given to the article and the tag reader since the tag only transmits at the timing defined in advance. Therefore, after the tag communicates with the tag reader, to where the article with the tag is carried to is not known until the relevant tag establishes the next communication with the tag reader. Further, as more time elapses from the last communication with the tag reader, the possibility that the article with the tag is near the tag reader that was communicating last lowers, needless to say. Thus, for the user to find the article by means of such system, the user himself must recall the memory and bring back the memory of where he moved to, where he placed the article and the like from the location of the article provided in response to the inquiry of the search, and thus the article may not necessarily be easily found. This is a large issue in the prior art. In addition, since a plurality of tag readers must be arranged in the room for measuring the article position, it is a disadvantage in terms of cost. Moreover, the size of the tag itself becomes large and becomes difficult to be mounted on a small article, and the cost of the tag itself increases since the active tag with built-in battery is used. If a great number of articles with the tag are arranged in the room, it becomes difficult to control the transmission timing of each tag in order to sense all the tags.
In patent document 3, a plurality of tag readers must be arranged in the room and thus is disadvantageous in terms of cost, similar to patent document 2. Further, the size of the tag itself becomes large and the cost increases since the data tag and the personal tag also perform wireless transmission.
Therefore, the present invention aims to provide an article position estimating apparatus, a method of estimating article position, an article search system, and an article position estimating program that does not require the idea of recalling the memory when the user looks for the article based on a simple configuration of the prior art, that is, the configuration in which the tag is given to the article, the minimum number of tag readers are arranged in the environment where the article is managed, and the relevant information is recorded only when the tag passes through the communication range of the tag reader.